Nitrates and nitrites are common and abundant components found in many fertilizers. As a result, the nitrates and nitrites may leach into ground water and eventually water bodies, such as lakes, rivers, and municipal water supplies. Depending on what happens to the nitrates and/or nitrites along the way to the water, nitrogen rich hydroxylamines may also be produced. The result is that nitrates, nitrites and/or hydroxylamines may be found in unnaturally high concentrations in fresh water bodies across the world. This may cause harmful algal blooms to proliferate and create “dead zones” because of the deoxygenation of the water. These ecologic “dead zones” with low or zero-oxygen (O2 gas) environments result in loss or abandonment of aquatic life in freshwater resources.
Conventional techniques for removal of nitrates and/or nitrites from groundwater may include membrane separation, ion exchange, and biological denitrification. Membrane separation is an expensive technique that uses a semipermeable membrane to separate nitrate from groundwater. Conventional ion exchange techniques exchange nitrate for other ions such as chloride, but generate nitrate-containing waste. Biological denitrification uses microorganisms to reduce nitrates and nitrites to nitrogen. The problem with this process is a wide variation of nitrate reduction selectivity and the potential development of pathogenic bacteria in water.
The conventional techniques for removal of nitrates and nitrites from water discussed above all have significant issues when used on large scales. One ideal option is to reduce nitrates, nitrates and/or hydroxylamines in water to other non-harmful nitrogen-containing products such as nitrogen gas.